A CFD Application

In this section we discuss another significant HPJava application code.
This code solves the Euler equations for inviscid fluid flow by
a finite volume approach. One version of this code, viewable at
http://www.hpjava.org/demo.html also has
a novel parallel GUI implemented in HPJava.

The Euler equations are a family of conservation
equations, relating the time rates of change of various densities to
divergences of associated flow fields. In two dimensions
there are four densities--the ordinary matter density,
densities of the two components of momentum, and the energy density.
The Euler equations can be summarized as a conservation equation for
four-component vectors , and :

(1)

The flow variables are related to the dependent variables
by simple (but non-linear) algebraic equations.
So the set of differential equations is closed.
Two important quantities that figure in the equations are
the pressure, , and the enthalpy per unit mass, ,
which can be computed from the components of using the equations of
state for the fluid.